When I was an adviser to the German government almost 15 years ago, I advocated that the nation become climate neutral as a transitional stage on the way towards a sustainable world. With that world ever further off, I have changed my mind. We must cut carbon emissions to zero in absolute terms, not merely to net zero.
Climate neutrality, in which emissions are offset by other measures, has led to oxymorons such as ‘clean diesel’ and ‘clean coal’. It is used to ‘greenwash’ environmentally damaging policies. The capture and storage of carbon dioxide and the manufacture of ‘blue hydrogen’ from natural gas can increase the use of fossil fuels, for example (see A. Brown Nature Clim. Change 2, 644; 2012). The use of biofuels and biomass can increase the consumption of energy, water and pesticides, and worsen air pollution (see go.nature.com/3bdcz7x).
To eliminate all carbon emissions, we must phase out coal and natural gas, as well as, in my view, nuclear power (see go.nature.com/3bdcv7x). We must switch to sources that are 100% renewable, such as wind, solar, hydro and geothermal — something that will hopefully start to happen in Germany after September’s elections. Crucially, the climate conference COP26, to be held in November, in Glasgow, UK, must end the greenwashing and launch a new era of real climate protection.
Nature 591, 34 (2021)